<!doctype HTML>
<!-- Test passes if it does not crash. -->
 <body style="opacity:0.5">
<div style=" -webkit-mask-box-image-source: url();" >
</div>
<div style="box-shadow: 1px 1px black; padding-block-start: 1px; isolation: isolate">
<div style="isolation: isolate"></div>
</body>
